Nitrogen dynamic of different organs of the energy plant Triarrhena sacchariflora during autumn

The objective of this study was to determine whether nitrogen re-translocation was present in the above-ground organs of Triarrhena sacchariflora during autumn. A successive sampling of the energy plant T. sacchariflora was conducted during autumn, and the nitrogen contents in different organs were determined. The results showed that (1) the nitrogen contents in the panicle and stem were the highest and lowest, respectively, among all organs; (2) the nitrogen contents in the panicle, leaf, and stem exhibited gradual decreases, while gradual increases were found in the root and rhizome over time. And the nitrogen contents of the panicle, leaf, and stem samples required at the last time were significantly (P < 0.05) lower by 69.97%, 33.62%, and 32.00%, respectively, when compared with the initial values. The nitrogen contents of the root and rhizome samples required at the last time were significantly ( P < 0.05) higher by 63.86% and 19.90%, respectively, when compared with the initial values; (3) The nitrogen re-translocation of the panicle and stem began after seed formation and lasted longer than that in leaf, while the nitrogen re-translocation of the leaf began later and finished before the first frost. In conclusion, there was obvious nitrogen re-translocation in the above-ground organs of the energy plant T. sacchariflora.